package day3;

import java.util.Scanner;

public class Demo3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int a = scanner.nextInt();

        if (a >= 90){
            System.out.println("优");
        } else if(a >= 80){
            System.out.println("良");
        } else if(a >= 70){
            System.out.println("中");
        } else if (a >= 60){
            System.out.println("及格");
        } else{
            System.out.println("差");
        }
    }
}
